The invention relates to medical devices, and in particular to devices, means, or systems used in cardiovascular studies, treatments, or investigations. Specifically, the invention relates to devices used for blood studies of infants.
A need has existed for an improved means and method for sampling and monitoring the blood system of infants, and more particularly premature infants. This present invention provides a device to improve the existing means and methods.
In new born infants, particularly infants born prematurely, there is often a problem with lungs that do not inflate properly. As a result, the baby does not get enough oxygen for proper life support. This premature lung syndrome in premature infants is called Hyaline Membrane Disease.
While sampling and monitoring the blood system infants that are born at term may encounter the same problems, the need for such sampling and monitoring is usually not required. The present invention may be used on term infants as well as on premature infants.
The sampling and monitoring of the blood in new born infants is performed by inserting a catheter into the umbilical artery at the umbilical stump (the shortest section of the umbilical cord that remains at the infant's body after the surgical procedure at birth).
One of the two umbilical arteries in the umbilical stump is used for the blood sampling and monitoring in new born infants. The sampling and monitoring is performed by passing a catheter into one of the umbilical arteries.
Inserting the catheter into the artery is difficult. The two umbilical arteries and an umbilical vein in the umbilical stump are surrounded by, and more or less held in place, by Wharton's Jelly, a jelly-like substance. The jelly-like substance really provides no firm support to the umbilical arteries, particularly in regard to the need for support as hereinafter described in conjunction with the insertion of the aforementioned catheter.
The insertion of the catheter in an umbilical artery in the umbilical stump, in order to sample and monitor the blood, is usually done during the first three or four days of the baby's life, during which the need for critical information is important to the physician.
The umbilical stump extends or sticks up about one-half an inch above the abdomen. The catheter must be inserted a sufficient distance into the umbilical artery so that it is beyond the skin, past the sphincter-like muscle under the skin. The umbilical arteries go to the aorta at the heart and is the means for obtaining a central arterial blood sample to read arterial oxygen content or tension either intermittently or on a continuous second to second basis. The catheter may also be used to take a blood sample for analyzing various other medical determinations.
During the period of Hyaline Membrane Disease, the infant may be connected to a respirator or may be given supplementary oxygen if not enough is supplied by the lungs, in order to avoid brain damage. Time is important for the infant's safety in order to avoid the danger of brain damage. Thus, the monitoring of the blood sample is very important at the early stages just after birth. The faster the catheter can be put into the umbilical artery for the monitoring process, the better for the infant.
If too much oxygen is supplied, there may be a risk of retrolental fibroplasia (blindness). Thus, a further factor in the importance of a need for an easy and quick means of inserting the catheter for monitoring purposes.
When the catheter is inserted in the umbilical artery, it is difficult, and any relative inexperience by the person inserting it can increase the difficulty. As there is no support in the aforementioned jelly-like substance, the artery end can be pushed down into the unsupportive jelly-like substance during the attempt to insert the catheter.
The prior art method is to use forceps to open or stretch apart the open entrance to the umbilical artery and hold it open, in a somewhat elliptical or rather flat elliptical configuration. Inserting the catheter into this unreceptive opening is difficult. Often the forceps will cut or tear pieces out of the edge of the artery, or as mentioned hereinbefore, the artery end gets pushed down into the jelly-like substance.
In the present invention, a funnel-like device, having the smaller or exit end taper to a diameter less than the inside diameter of the umbilical artery, is first inserted into the end of the umbilical artery at the surgically severed surface of the umbilical cord which then leaves the umbilical stump.
The funnel-like device has the tapered smaller or exit end formed into a plurality of sping-like prongs which will expand or move outwardly as the catheter is inserted and permit it to pass through. Thus, initially the tapered end is very small to permit insertion into the umbilical artery, but is expandable to permit the larger catheter to pass through and into the umbilical artery.
Funnel-like devices have been used in the prior art for guiding tools and other items in a specific direction, but were not of a structure that permitted an expanded configuration. However, there is a special problem with merely inserting such a funnel-like means into an artery-type interior, the artery has a tendency to exude the item being inserted as another item is passed through it.
When inserting a funnel-like device into an artery, as described hereinbefore, and then passing a catheter through it, the smooth muscle of the artery contracts around the catheter and concurrently squeezes or exudes an ordinary encircling ring, such as the funnel-like end, out of the artery.
To overcome this exuding action the present invention is bulbous-like on the end. Thus, as the smooth muscle artery contracts and closes and squeezes around the cathether it also contracts and closes and squeezes around the end of the funnel-like device. However, the bulbous-like end permits the contraction to close around the top and over the bulbous end, thus preventing it from being exuded from the artery. A novel and unique feature in the present invention.
As the lead tips under the bulbous end and then the bulbous end is inserted into an artery the device may be held with a forceps above the bulbous end, an additional advantage of the novel and unique device, until the catheter is inserted. The bulbous end may normally be inserted approximate one-quarter inch below the surface of the umbilical stump, sufficient to prevent being exuded.
After the catheter is in place the introducer, the funnel-like device, may be left in place, slipped out of the artery and partially up the catheter, or it may be cut off for disposal.
With care afforded by the facility of the catheter monitoring system introduced by the present invention, the lung problem usually is resolved in the first three or four days of the infant's life and the catheter is removed. This also guards against infection if longer periods were used. The catheters may range up to approximately one-eighth inch in diameter.
The plurality of prong-like ends may be formed by mere slits or by a keyhole-like separation.
It is, therefore, an object of the invention to provide a device for introducing a catheter into an artery that may be used on new born infants.
It is another object of the invention to provide a device for introducing a catheter into an artery that is funnel-like in configuration to receive and guide a catheter.
It is also an object of the invention to provide a device for introducing a catheter into an artery that has a plurality of prong-like nibs at the end that may be expanded outwardly as an object passes therethrough.
It is yet another object of the invention to provide a device for introducing a catheter into an artery that has a bulbous end on a plurality of prong-like nibs to provide a means for preventing a smooth muscle artery from exuding the device.
Further objects and advantages of the invention will become more apparent in the light of the following description of the preferred embodiments.